Combined gage and signal device.



PATENTED MAY 5, 1908.

M. G. MELVIN.

COMBINED GAGE AND SIGNAL DEVICE.

APPLICATION FILED MAR-16, 1907.

' Snveufoz flari 61. 278M112.

W18" woes UNITED STATES PATENT OFFICE.

MARK 3r. MELVIN, O F SURANTON, PENNSYLVANIA, ASSIGNOR OF ONE-HALF 'IO EDWARD A.

' JONES, ()F SCRANTON, PENNSYLVANIA.

COMBINED .GAGE AND SIGNAL DEVICE.

in circuitat either high or low predetermined limits of pressure or height of water.

The invention has for one of its objects to improve and simplify the construction and operation of devices of this character so as to be comparatively easy and inexpensive to manufacture, thoroughly reliable and eflicient in use, and capable of a large variety of applications, as for instance, it may be used as a )ressure indicator for steam boilers where y the pressure can be read at the boiler by means of the indicator dial and the an electric alarm located in the engineers ofiice or other remote point; or it .may be used to indicate the height of water in a tank and to signal when the tank is full or empty.

A further object of the invention is to provide a device includin an element sensitive to changes in pressure or actuating the hand of the indicator or gage and, to close an electric alarm containing circuit at predetermined abnormal limits.

With these objects in view and others, as will appear as the description proceeds, the invention comprises the various novel fee tures of construction and arrangement of parts which Will be more fully described here inafter and set forth with particularity in the claims appended hereto.

In the accompanying drawing, which illustrates one of the embodiments of the inven tion, Figure 1 is a front view of the gage or indicator. Fig. 2 1s a vertical longitudinal section thereof. Fig. 3 is a vertical transverse section on line 3 3, Fig. 2. Fig. 4 is a detail sectional view of a modified form of circuit closing device.

Similar reference character are employed to designate similar parts throughout the figures.

Referring to thedrawing, l desi nates the casing of the gage which may be 0 any suit- Specification of Letters Patent.

Application filed March 16, 1907.

maximum or minimum pressure indicated by Patented May 5, 1908.

Serial No. 362,683.

able character and mounted on a base plate 2 of wood, rubber or other insulating material. 011 the base plate is a hollow head 3 having a threaded coupling end 4 to which is coupled a pipe 5 which is connected with a boiler, tank or other apparatus in which the pressure or volume of the contents is to be gaged.

On the head 3 is mounted a flexible metal tube 6 that is sensitive to variations in pressure in the fluid or liquid of the system in,

which the gage is employed. This flexible element, which is of usual construetioi'i, is adapted to operate a double-pointed needle or hand 6 mounted on a horizontal arbor 7 by means of a pinion 8 on the arbor meshing with a sector rack 9 that receives motion through the link 10. The rack frame 1 1 oscillates on a shaft 12, which, with the arbor 7, is mounted on spacedv uprights or stand ards 13 secured on the top of the head 3,

By this means, the handis actuated as the pressure in the pipe 5 and. element 6 varies. On the head 3 is a lateral extension 14 that bears on the top surface of the base plate 2 and is held in position thereon by the upper end of the pipe 5 bearing against the bottom surface of the plate.

The movement of the flexible element 6 is also utilized for controlling an electric circult that contains an audible or other signal for indicating either abnormal extremes of pressure or volume of the apparatus with which the gage is used. For this purpose, the free end of the element 6 has a laterally extending arm 15 movable between adjustable contacts 16 supported on an upright frame 17. 'lhisframe is provided with a binding post 18 for connecting it with one side of a circuit including a source of current, and the frame is adjustable toward or away from the element 6 by providing the base plate 2 with a slot 19 through which the shankof the screw 20 of the binding postex-- tends, the said screw having a clamping nut 21 for firmly securing the frame 17 in position. The head 3 is provided with a binding post 22 with which is connected the opposite side of the electric circuit, and when by ex cessive movement of the element 6, the corn tact 15 engages either one of the contact. screws 16, the circuit is completed through the binding post 18, frame 17, either one of the screws 16, flexible element 6, head 8, binding post 22 and back to the source of current supply.

In practice, assuming the g e to be used in connection with a steam bo1 er, the divisionsin the outer circle of the dial of the gage are emplo ed for reading the pressure of the steam in t e boiler in pounds per square inch. The adjustable screws 16 are set to enable the flexible element 6 to close an electric circuit when the abnormal low or high limits of pressure at'which the system is intended to 0 crate is reached. The pressure gage enahles the fireman to know at a glance what the pressure of the steam in the boiler is, while the electric alarm which may be located in the engineers office or any other desired oint, forms a safety indicating means whereby abnormal conditions may be revealed and instructions immediately given for their correction.

When the device is to be used in connection with a feed water tank for indicating the level, the inner circle of divisions on the dial of the gage is employed and the user divides this circle into units corresponding to the number of feet in the height of the tank, as

I for instance, in a ten-foot tank, the range of movement of the upper end of the hand 6 corresponding to a full or empty tank, would be divided into ten units so that the height of water in the tank would be indicated by the position of the upper end of the hand 6 with relation to this scale. The screws 16 would then be adjusted to such a position that the circuit would be completed when the tank was either full or empty, thus sounding the alarm. and warning the engineer that the water supply must be either opened or closed, as the case may be.

In the modification shown in Fig. 4, the free end of the flexible element 6 carries a contact 23 having a binding post that is mounted on a block of insulation 24 secured to the said element and the contact 23 is adapted to make contact with either one of the adjustable contact screws 25 when the flexible element reaches either extreme limit of its movement. In this form, the circuit is completed through the binding post connected with the frame 17, either one of the screws 25, contact 23, and backt-o the source of supply.

5 From the foregoingdescription, taken in connection with the accompanying drawing, the advantages of the construction and of the method of o eration will be readily apparent to those skil ed in the art to which the invention appertains, and while I have described the principle of operation of the invention, together with the apparatus which I now consider to be the best embodiment thereof, I desire to have it understood that the apparatus shown is merely illustrative and that such changes may be made when desired, as are within the scope of theclaims.

saaass Having thus described the invention, what I claim is 1. In an apparatus of the class described, the combination of an indicator or gage including a flexible element sensitive to pressure variations, with an alarm COIltBJIllIl" circuit, and a switch actuated by the said element for controlling the circuit, said switch com rising a contact carried by and mounted dlrectly on the movable element, means for connectin one side of the circuit thereto, and a pair of adjustable contacts disposed on opposite sides of the first-mentioned contact and connected with the opposite side of the circuit.

2. In an apparatus of the class described, the combination of an indicator including a flexible element sensitive to pressure variation, with a signal-containing circuit, a binding post connected with the element, and a switch for controlling the circuit at either extreme limit of movement of the element, said switch comprising a contact fixed on the element, a frame connected with the circuit, adjustable contact screws on the frame disposed at opposite sides of the first-mentioned contact, and a binding 0st on the frame.

3. In an apparatus 0 the class described, the combination of an indicator comprising a base-plate, adial mounted thereon, a flexible element sensitive to ressure variations,

a needle movable over t e dial, and means between the flexible element and needle for actuating the latter, with an alarm including circuit, and a switch for controlling the circuit, said switch comprising a contact-carrying frame adjustablebodily back and forth on the base plate, contacts on the frame, and

a contact on the flexible element to directly engage the first-mentioned contacts.

4. In anapparatus of the class described, the combination of a base plate having an aperture, a head provided with a flange en gaging one side of the base plate and rovided with a tubular portion exten ing through the opening of the latter, a pipe communicating with the head and connected with the said portion for holdin the head in fixed position on the plate, a landing post connected with the head, a flexible element communicating with the head and sensitive to pressure variation, a contact carried by the element, said'element forming part of a circuit, a stationary contact arranged in cooperative relation with the contact on the e ement, and a binding post for connecting the conductor with the stationary contact. In testimony whereof, I affix my signature in presence of two witnesses.

MARK G. MELVIN. Witnesses: J. W. CARPENTER,

WALLACE G. Mosna. 

